DNA microarrays and other massively parallel screening technologies are redefining the approach to discovery in biomedical research. The use of small sample volumes in these techniques presents unique challenges and opportunities for design of novel uniform mixing technologies. Typical DNA microarray analysis often discards up to 99 percent of the data obtained, limiting results to only the largest changes in hybridization signals that can be reliably detected with the current technology. One of the reasons for this is inadequate design of the hybridization chamber itself. Slide-coverslip hybridization methods in current use rely on diffusion to uniformly deliver target DNA to the complete set of probe spots across the array. A simple examination of the diffusion characteristics of these solutions suggests that this will produce wide variations in target DNA delivery and similar variations in the hybridization data of these experiments. Novel designs are proposed to achieve a more uniform mixing of the target DNA in the small volumes required for these experimental designs. In phase I of this project, these designs will be evaluated and optimized for DNA microarray hybridizations.